School-slate



. (NoModel.)

C. F. RAPP. School Slate.

Patented Sept. 21, 1880.

/ Y Il Y UNITED STATES` PATENT OEEieE.

CHRISTIAN F. RAPP, OF CINCINNATI, OHIO.

SCHOOL-SLATE.

SPECIFICATION forming part of Letters Patent No. 232,416, dated September 21, 1880.

Application mea May 19, issu. (No model.)

To all whom @t may concern:

Be it known that I, CHRISTIAN F. RAPP, ot' the city of Cincinnati, coun ty ofHamilton, State of Ohio, have invented a new and useful Improvement in School-Slates, ot' which the following is a specification.

This invention relates to that class of reversible slates in which a slender cylindrical wire or rod is bent or looped from one member to the other, the opposite bends or loops being embedded in or united to the opposite folding members to permit them to fold upon each other in either direction. This class of slates is represen ted in Letters Patent Nos. V186,443 and 186,621 granted to me, dated January 23, 1877, and my Patent No. 203,293, dated May 7 1878.

7The various gures of the drawings hereto annexed are perspective views of slate-frames united in pairs by various forms of my bent- \vire connectingdevice. In Figure lthe frameconnectingdevicehas but two transversebends. In Fig. 2v the wire has a greater number of bend s. In Fig. 3 the opposite pintle portions of the wire are rigidly united in the center by the cross-link. In Fig. 4 are shown two coupling devices, similar tothe one shown iu Fig. 3, the upper o'ne in section and exposed, while the lower is embedded in the edge ofthe frame. Fig. 5 shows the frames united b v two wires, similar to the form shown in Fig. 1. These are twisted together between the bends, and the central twisted part is between the -frames. In Fig. 6 the central part of the wire, between the transverse links and the parts outside of the links, are embedded in one of the folding members. Two transverse loops exten d across to the opposite member, and vare secured by staples, thus uniting the frames together. In Fig. 7 the ends of the wire only are embedded. The central longitudinal part is between the frames. Fig. 8 shows a form similar to Fig. 5, except that the ends are bent back in the direction of the central part, which is also between the frames. In Fig. 9 the connectinglink is similar to Figs. 3 and 4:; butin this case the ends of the wire are attened to enter corresponding perforations inalat metal crosslink to rigidly unite the longitudinal parts and prevent either turning independently of the other. 1

In the forms of coupling device iu which the connecting-link has its longitudinal portions all embedded in the edges ot the respective frames A, the edges of these frames are a plain haltround; but in the forms shown in Figs. 5, 7, and 8, in which the central connectingpieces between the cross-links are between the edges of the frame, the edges are beaded, as shown. The object of this is to provide abed for the exposed longitudinal part ofthe wire B, so that when the slates are closed the flat surfaces ot' the frames may fold closely together.

The edges of the slate-frames are grooved where they are to receive the pivotal parts of the coupling device B, and notched transversely where the pivotal portions are united by the cross-bends, as in my former patents above referred to, so that the transverse bends may assume a position perpendicular to the faces ot' the frames when folded.

The wire B is secured in place inthe edges ot' the frames by the insertion of glued wooden strips or cleats, or by staples, or both staples and cleats, if desired. The staples may be driven over the wire and the cleats omitted. In this case it would make no difference were the wood upon each side of the groove cut away. Or the staples may bedriven over the cleats to hold them firmly in placein case the glue should be dissolved by washing the slate.

It is evident that the grooving of the edges may be entirely omitted. Take the iorm, for

instance, represented by Fig. 7. By removing the bayonet-shaped ends in front of the fastening-staples, turning the end of the wire into an eye Varound the staple, and making a een` tral loop, similar to the ones shown, to enter a transverse notch in the middle ot the opposite frame, and securing it in the same way by a staple, and a pair of reversible slates are produced without groovin g either frame. Two or more of these loops may be made to enter and be secured in each of the opposite members of the slate.

In Fig. 8 I have shown a form which requires but one extraneous fastening device in each frame. The opposite members are grooved at the diagonally-opposite corners. The corners opposite the grooves are bored in from the end. The bent end of the wire is slipped into the hole in one frame, the opposite frame slipped over the diagonally-opposite pintle; the other pintles can now be turned into their respective grooves and secured by cleats or staples, in the usual Way.

The form of hin ge-wire shown in Figs. 3 and 4 may have the transverse portions either brazed to the longitudinal portions, or made of two Wires and the cross port-ions twisted, as in Fig. 5.

The couplingwire may be bent in various Ways, (not sho\vn,) or divisions and variations of the shown forms used, Without varying the principle of the invention, which consists, essentially, in bending or looping the Wire and connecting the opposite bends to the opposite folding members.

I claim 1. A pair of sla/teframes, A A, in combination with the bent-Wire coupling device B, the opposite bends of which are embedded in or connected to the opposite folding members A A, substantially as shown, and for the purpose set forth.

2. The double reversible slate consisting of a pair of round edged and longitudinallygrooved and transversely-notched leaves, A A, and the rod or wire B, bent or formed at the extremities into the bayonet-like form shown, the Whole being arranged, secured, and adapted to operate substantially as set forth.

CHRISTIAN F. RAPP.

Witnesses:

C. MyLoTzE, GEO. J. MURRAY. 

